Expert Experience and Data-Driven Based Hybrid Fault Diagnosis for High-SpeedWire Rod Finishing Mills

The reliable operation of high-speed wire rod finishing mills is crucial in the steel production enterprise.As complex system-level equipment,it is difficult for high-speed wire rod finishing mills to realize fault location and real-time monitoring.To solve the above problems,an expert experience and data-driven-based hybrid fault diagnosis method for high-speed wire rod finishing mills is proposed in this paper.First,based on its mechanical structure,time and frequency domain analysis are improved in fault feature extraction.The approach of combining virtual value,peak value with kurtosis value index,is adopted in time domain analysis.Speed adjustment and side frequency analysis are proposed in frequency domain analysis to obtain accurate component characteristic frequency and its corresponding sideband.Then,according to time and frequency domain characteristics,fault location based on expert experience is proposed to get an accurate fault result.Finally,the proposed method is implemented in the equipment intelligent diagnosis system.By taking an equipment fault on site,for example,the effectiveness of the proposed method is illustrated in the system.

Surface Integrity of Inconel 738LC Parts Manufactured by Selective Laser Melting Followed by High-speed Milling

This study is concerned with the surface integrity of Inconel 738LC parts manufactured by selective laser melting(SLM)followed by high-speed milling(HSM).In the investigation process of surface integrity,the study employs ultradepth three-dimensional microscopy,laser scanning confocal microscopy,scanning electron microscopy,electron backscatter diffractometry,and energy dispersive spectroscopy to characterize the evolution of material microstructure,work hardening,residual stress coupling,and anisotropic effect of the building direction on surface integrity of the samples.The results show that SLM/HSM hybrid manufacturing can be an effective method to obtain better surface quality with a thinner machining metamorphic layer.High-speed machining is adopted to reduce cutting force and suppress machining heat,which is an effective way to produce better surface mechanical properties during the SLM/HSM hybrid manufacturing process.In general,high-speed milling of the SLM-built Inconel 738LC samples offers better surface integrity,compared to simplex additive manufacturing or casting.

Extraction Fuzzy Linguistic Rules from Neural Networks for Maximizing Tool Life in High-speed Milling Process

In metal cutting industry it is a common practice to search for optimal combination of cutting parameters in order to maximize the tool life for a fixed minimum value of material removal rate（MRR）. After the advent of high-speed milling（HSM） pro cess, lots of experimental and theoretical researches have been done for this purpose which mainly emphasized on the optimization of the cutting parameters. It is highly beneficial to convert raw data into a comprehensive knowledge-based expert system using fuzzy logic as the reasoning mechanism. In this paper an attempt has been presented for the extraction of the rules from fuzzy neural network（FNN） so as to have the most effective knowledge-base for given set of data. Experiments were conducted to determine the best values of cutting speeds that can maximize tool life for different combinations of input parameters. A fuzzy neural network was constructed based on the fuzzification of input parameters and the cutting speed. After training process, raw rule sets were extracted and a rule pruning approach was proposed to obtain concise linguistic rules. The estimation process with fuzzy inference showed that the optimized combination of fuzzy rules provided the estimation error of only 6.34 m/min as compared to 314 m/min of that of randomized combination of rule s.

Investigation of Surface Roughness in High-Speed Milling of Aeronautical Aluminum Alloy

An approach is presented to optimize the surface roughness in high-speed finish milling of 7050- T7451 aeronautical aluminum alloy. In view of this, the multi-linear regression model for surface roughness has been developed in terms of slenderness ratio, cutting speed, radial depth-of-cut and feed per tooth by means of orthogonal experimental design. Variance analyses were applied to check the adequacy of the predictive model and the significances of the independent input parameters. Response contours of surface roughness were generated by using response surface methodology （RSM）. From these contours, it was possible to select an optimum combination of cutting parameters that improves machining efficiency without increasing the surface roughness.

Influence of High-Speed Milling Process on Mechanical and Microstructural Properties of Ultrafine Grained Profiles Produced by Linear Flow Splitting

The effects of milling parameters on the surface quality,microstructures and mechanical properties of machined parts with ultrafine grained(UFG)gradient microstructures are investigated.The effects of the cutting speed,feed per tooth,cutting tool geometry and cooling strategy are demonstrated.It has been found that the surface quality of machined grooves can be improved by increasing the cutting speed.However,cryogenic cooling with CO_2 exhibits no significant improvement of surface quality.Microstructure and hardness investigations revealed similar microstructure and hardness variations near the machined groove walls for both utilized tool geometries.Therefore,cryogenic cooling can decrease more far-ranging hardness reductions due to high process temperatures,especially in the UFG regions of the machined parts,whilst it cannot prevent the drop in hardness directly at the groove walls.

Application of On-Line Rail Milling in Rail Maintenance of High-Speed Railways

On-line rail milling technologies have been applied in rail maintenance, and are proving to be efficient and environmental friendly. Based on the field data of on-line rail milling, a program for comparing rail transverse profiles before and after milling was designed and the root mean square （RMS） amplitude of longitudinal profile was calculated. The application of on-line rail milling technology in removing rail surface defects, re-profiling railhead transverse profiles, smoothing longitudinal profiles and improving welding joint irregularity were analyzed. The results showed that the on-line rail milling technology can remove the surface defects at the rail crown and gauge comer perfectly, re-profile railhead transverse profile with a tolerance of - 1. 0-0.2 ram, improve longitudinal irregularity of rail surface, with the RMS amplitude of irregularity reduced more than 50% and the number of out-of- limited amplitude reduced by 42% - 82% in all wavelength ranges. The improvement of welding joint irregularity depends on the amount of metal removal determined by the milling equipment and the primal amplitude.

Surface Topography and Roughness of High-speed Milled AlMn1Cu

The aluminum alloy AlMn1Cu has been broadly applied for functional parts production because of its good properties. But few researches about the machining mechanism and the surface roughness were reported. The high-speed milling experiments are carried out in order to improve the machining quality and reveal the machining mechanism. The typical topography features of machined surface are observed by scan electron microscope（SEM）. The results show that the milled surface topography is mainly characterized by the plastic shearing deformation surface and material piling zone. The material flows plastically along the end cutting edge of the flat-end milling tool and meanwhile is extruded by the end cutting edge, resulting in that materials partly adhere to the machined surface and form the material piling zone. As the depth of cut and the feed per tooth increase, the plastic flow of materials is strengthened and the machined surface becomes rougher. However, as the cutting speed increases, the plastic flow of materials is weakened and the milled surface becomes smoother. The cutting parameters （e.g. cutting speed, feed per tooth and depth of cut） influencing the surface roughness are analyzed. It can be concluded that the roughness of the machined surface formed by the end cutting edge is less than that by the cylindrical cutting edge when a cylindrical flat-end mill tool is used for milling. The proposed research provides the typical topography features of machined surface of the anti-rust aluminum alloy AlMn1Cu in high speed milling.

Design and Implementation of Dynamic High-Speed Switches in Super Base Station Architectures

Novel centralized base station architectures integrating computation and communication functionalities have become important for the development of future mobile communication networks.Therefore,the development of dynamic high-speed interconnections between baseband units(BBUs)and remote radio heads(RRHs)is vital in centralized base station design.Herein,dynamic high-speed switches(HSSs)connecting BBUs and RRHs were designed for a centralized base station architecture.We analyzed the characteristics of actual traffic and introduced a switch traffic model suitable for the super base station architecture.Then,we proposed a data-priority-aware(DPA)scheduling algorithm based on the traffic model.Lastly,we developed the dynamic HSS model based on the OPNET platform and the prototype based on FPGA.Our results show that the DPA achieves close to 100%throughput with lower latency and provides better run-time complexity than iOCF and HE-iSLIP,thereby demonstrating that the proposed switch system can be adopted in centralized base station architectures.

Research on dynamic characteristics of high speed milling force based on discontinuous functions

This paper begins with a consideration of the influence of feed per revolution upon the depth of a cut and the impact of the machining method on the direction of tool pressure average and subsequent description of efficient cutting directions and the methods for load cell orientation. The paper goes further into the key conclusions concerning the dependences of the cutting depth at high-speed milling as in the case of discontinuous functions. It ends with recommendations offered for positioning of load cells for cut-up milling and cut-down milling.

Energy field-assisted high-speed dry milling green machining technology for difficult-to-machine metal materials

Energy field-assisted machining technology has the potential to overcome the limitations of machining difficult-to-machine metal materials,such as poor machinability,low cutting efficiency,and high energy consumption.High-speed dry milling has emerged as a typical green processing technology due to its high processing efficiency and avoidance of cutting fluids.However,the lack of necessary cooling and lubrication in high-speed dry milling makes it difficult to meet the continuous milling requirements for difficult-to-machine metal materials.The introduction of advanced energy-field-assisted green processing technology can improve the machinability of such metallic materials and achieve efficient precision manufacturing,making it a focus of academic and industrial research.In this review,the characteristics and limitations of high-speed dry milling of difficult-to-machine metal materials,including titanium alloys,nickel-based alloys,and high-strength steel,are systematically explored.The laser energy field,ultrasonic energy field,and cryogenic minimum quantity lubrication energy fields are introduced.By analyzing the effects of changing the energy field and cutting parameters on tool wear,chip morphology,cutting force,temperature,and surface quality of the workpiece during milling,the superiority of energy-field-assisted milling of difficult-to-machine metal materials is demonstrated.Finally,the shortcomings and technical challenges of energy-field-assisted milling are summarized in detail,providing feasible ideas for realizing multi-energy field collaborative green machining of difficult-to-machine metal materials in the future.

Yang-Mills理论、维度正规化及其它

首先介绍了 1999年度诺贝尔物理学奖得主 ,胡夫特和维尔特曼的维度正规化方案 .然后简要阐述Yang -Mills理论的基本思想、发展概况 ,尤其是其中的重整化问题和真空对称性自发破缺机制 ,评述了作为 2 0世纪量子论发展的最高阶段———量子化的Yang -Mills理论 ,对于整个物理学 ,尤其是基本粒子的基本相互作用理论的巨大贡献 .最后展望了 2 1世纪物理学发展的趋向 .

Tool Life and Surface Integrity in High-speed Milling of Titanium Alloy TA15 with PCD/PCBN Tools

Titanium alloys are widely used in aeronautics that demand a good combination of high strength, good corrosion resistance and low mass. The mechanical properties lead to challenges in machining operations such as high process temperature as well as rapidly increasing tool wear. The conventional tool materials are not able to maintain their hardness and other mechanical prop- erties at higher cutting temperatures encountered in high speed machining. In this work, the new material tools, which are poly- crystalline diamond （PCD） and polycrystalline cubic boron nitride （PCBN） tools, are used in high-speed milling of Ti-6.5AI-2Zr-IMo-IV （TA15） alloy. The performance and wear mechanism of the tools are investigated. Compared to PCBN tool, PCD tool has a much longer tool life, especially at higher cutting speeds. Analyses based on the SEM and EDX suggest that attrition, adhesion and diffusion are the main wear mechanisms of PCD and PCBN tools in high-speed milling of TA 15. Oxida- tion wear is also observed at PCBN tool/workpiece interface. Roughness, defects, micro-hardness and microstructure of the ma- chined surface are investigated. The recorded surface roughness values with PCD/PCBN tools are bellow 0.3 μm at initial and steady cutting stage. Micro-hardness analysis shows that the machined surface hardening depth with PCD and PCBN tools is small. There is no evidence of sub-surface defects with PCD and PCBN tools. It is concluded that for TA15 alloy, high-speed milling can be carried out with PCD/PCBN tools.

Underground void filling by cemented mill tailings

Underground mining always create voids.These voids can cause subsidence of surface.So it is always a demand to fill the void in such a manner that the effect of underground mining can be minimized.Void filling using mill tailings especially in metal mining is one of the best techniques.The tailings produced in milling process have traditionally been disposed in tailing ponds creating a waste disposal and environmental problems in terms of land degradation,air and water pollution,etc.This disposal practice is more acute in the metal milling industry where the fine grinding,required for value liberation,results in the production of very fine tailings in large percentage.This paper includes discussions on the effectiveness of different paste mixes with varying cement contents in paste backfilling operations.The results revealed that material composition and use of super plasticizer strongly influenced the strength of cemented backfill.

Chip morphology and cutting temperature of ADC12 aluminum alloy during high-speed milling

The ADC12 aluminum alloy is prone to severe tool wear and high cutting heat during high-speed milling because of its high hardness.This study analyzes the highspeed milling process from the perspective of different chip morphologies.The influence of cutting temperature on chip morphology was expounded.A two-dimensional orthogonal cutting model was established for finite element analysis(FEA)of high-speed milling of ADC12 aluminum alloy.A theoretical analysis model of cutting force and cutting temperature was proposed based on metal cutting theory.The variations in chip shape,cutting force,and cutting temperature with cutting speed increasing were analyzed via FEA.The results show that,with the increase in cutting speed,the chip morphology changes from continuous to serrated,and then back to continuous.The serrated chip is weakened and the cutting temperature is lowered when the speed is lower than 600 m·min^(-1)or higher than 1800 m·min^(-1).This study provides a reference for reducing cutting temperature,controlling chip morphology and improving cutting tool life.

Experimental Study on Machining Shape Hole of Ni-based Super-heat-resistant Alloy

Inconel 718 and Waspaloy, Nickel-based super-heat-resistant alloy, are high-strength, thermal-resistant and corrosion-resistant alloy that are widely used in parts of gas turbines and airplane engines. Due to their extremely tough and thermal-resistant nature, they are well known as materials that are difficult to cut. Shape holes on a disc of an aircraft engine, made of Ni-based super-heat-resistant alloy, are required with good surface integrity and geometric accuracy. This kind of shape hole is produced by EDM (Electro-discharge machining) currently. It is necessary to investigate an alternative machining process to reduce the process time and improve the surface quality. This paper presents an experimental study on the machining methods for the shape hole of Ni-base super-heat-resistant alloy Inconel 718 and Waspaloy. The feasibility using milling or/and grinding as an alternative for currently EDM process to machine shape holes is assessed by observing the wear and breakage of the cutting tools and grinder and analyzing the hole surface integrity and geometric accuracy. The results show that the milling process of Inconel 718 and Waspaloy can produce shape holes with acceptable surface roughness and geometric accuracy efficiently. The machined Waspaloy shape holes reveal a slight decrease tendency in section dimension from the top of the its bottom. There is a larger deviation from the nominal profile at the segment with smaller radius. A thin softened surface layer with thickness smaller than 60 μm occurs on the machined Waspaloy shape holes. The softening and work hardening become remarkable with the progress of tool wear.

球磨法制备超粗及特粗晶硬质合金研究进展

本文概述了国内外关于球磨法制备超粗及特粗晶硬质合金的研究进展,阐述了轻度球磨法、高能搅拌球磨法、纳米活化法等几种粉末处理方法制备超粗及特粗晶硬质合金的工艺特点和合金性能。分析了这几种方法在制备超粗及特粗晶硬质合金面临的技术质量风险,说明了球磨法制备超粗及特粗晶硬质合金的低成本、易普及优势,提出了提升轻度球磨在球磨强度和球磨时间等参数综合控制以及配套开发晶粒更粗、结晶完整的WC粉原料等发展建议。

The Long Magenstrasse in the Treatment of Super Obese Patients (Results over 5 Years after Surgery)

Background: The considerable increase in Obesity and especially the increase in super obese patients (Body Mass Index—BMI ≥ 50 Kg/m2) who require surgery lead doctors to search for surgery techniques which give good results in terms of a consistent and stable weight loss associated with low morbidity and good quality of life. The Long Magenstrasse (LM) intervention, born from combining two properly modified surgical procedures (Selective Vagotomy with pyloric divulsion and Mangestrasse & Mill by Johnston) seems to have these characteristics according to our experience after operating on 660 patients. Methods: From October 2003 to October 2008 we treated 186 patients with LM. One hundred and sixty-two patients were regularly present to the annual follow-up, but 24 patients didn’t turn up, therefore, they were contacted by phone. On average, surgery lasted approximately 80 minutes (range: 50 - 90 minutes). Thirty patients were super obese with an average BMI of 57.4 Kg/m2;156 patients were grade II and III obese with an average BMI of 40.7 Kg/m2. Results: The average BMI of the 30 super obese patients decreased from 57.4 Kg/m2 to 35.9 Kg/m2 one year after surgery, to 35.6, 5 years after surgery and it has remained stable until now. In the 156 patients suffering from II and III grade obesity, the average BMI decreased from 40.7 Kg/m2 to 27.8 Kg/m2 one year after surgery and it has remained stable until now. Out of all super obese diabetic patients, only one has partially maintained his/her therapy. Patients have reported a decreased appetite since the very first days of post-operative period with an early sense of satiety which is unchanged until today. Conclusions: A consistent and stable weight loss over 5 years after surgery even in Super Obese patients, a decrease in appetite with an early sense of satiety, a re-equilibrium of the metabolic syndrome in particular of Diabetes Mellitus, allow to classify LM among those surgical treatments with a mixed mechanism of action: both restrictive and functional, in particular, entero-hormonal and gastric neurosecretory.

大型矿渣立磨等粉磨设备的结构特点及应用

介绍并分析了河北敬业集团一套年产200万吨超大型矿渣微粉系统的主要工艺流程、产品技术指标、粉磨设备结构形式选择、矿渣立磨选型,200万吨超大型矿渣微粉系统主要经济技术指标与两套年产100万吨系统、三套年产65万吨系统相比具有显著优势,得出超大型矿渣立磨的广泛使用以及进一步大型化是必然发展趋势的结论。

基于立盘式搅拌磨机的铁氧体磁粉超细磨影响规律研究

为了研究验证立盘式搅拌磨机对铁氧体磁粉超细磨效果的影响规律,基于试验室立盘式搅拌磨机试验平台进行正交试验,进行了搅拌盘直径、相邻搅拌盘间隙、空隙盘面积比、搅拌盘边缘线速度、搅拌盘数量5个关键参数对磨矿效果的影响规律研究。研究结果表明:以能耗作为考核指标,影响作用从大到小依次为搅拌盘转动速度、搅拌盘数量、搅拌盘直径、相邻搅拌盘间隙和空隙盘面积比;试验对比了北矿科技阜阳生产基地铁氧体磁粉的超细磨过程,使用立盘式搅拌磨机为超细磨设备,可降低吨能耗22.5%。

超微粉碎对脱脂米糠膳食纤维理化特性及组成成分的影响

采用超微粉碎对脱脂米糠膳食纤维进行处理,研究不同粒径的纤维粉体的理化特性及组成成分的变化。实验结果表明,随着超微粉碎程度的加强,粒径的不断减小,膳食纤维的持水力、持油力、膨胀力均有显著提高,而阳离子交换能力先增加后降低;膳食纤维经超微粉碎后,纤维素含量基本保持不变,而部分半纤维素转化为水溶物。